Shutter for cameras.



l. H. DOLBY. SHUTTER FOR CAMERAS. APPLICATION man muss. x911.

1,275,230. I Patented Aug. 13, 1918.

minim.

MI E 6 JESSE'H. IDOLBY, or ELGIN, rumors.

SHUTTER FOR CAMERAS.

Application filed May 16, 1917. Serial No. 169,018.

To all whom it may concern:

V Be it known that I,,-Jnssn H. DoLBY, a subject of the King of Great Britain, and a resident of Elgin, county Illinois, have invented certain new and useful Improvementsin Shutters for Cameras, of which the following is a specification.

y invention relates to shutters for cameras and has for its object the provision of a shutter that is adapted to beset manually and released through the medium of a destructible element. It is also an object of my invention to provide a camera shutter of this character that is justment so that relatively long or short exposures are possible struction of the shutter. A further object I have in view is the provision of a camera shutter of this type that is capable of being attached to cameras already in use, and one which may be readily and quickly installed on or removed from the camera without the use of tools for this purpose.

Other objects are the provision of a camera shutter that is dependable and efiieient in its operation, and comparatively inexpensive to manufacture,

camera. Other objects. and advantages of my invention will be obvious aft-er an understanding of the preferred construction and operation of the device is had, and I prefer to accomplish the divers objects by substantially the means and. in the manner hereinafter fully described and as more particularly pointed out in the claims, referencebeing Hereby made to the accompanying drawings forming a part hereof.

In the drawings I Figure 1 is a fragmental longitudinal'section of a camera, showing my invention' in side elevation applied to the lens opening of the camera-box.

Fig. 2 is a frontelevation of'my camera shutter.

Fig. 3 is a transverse section thereof taken through the lens opening. r

Fig. 4 is aview similar to Fig. 2 of a modified manner of setting the shutter and illustrating the device adjusted for greater speed than in Fig. 2. i Fig. 5 is a plan of a destruetible' element used in connection with the shutter.

Referring to the drawings, it will be seen suitable channeled holder that carries a mow Specification of Letters Patent.

of Kane, and State ofcapable of speedy ad without altering the con so that it may be sold at a small price as an attachment oran auxiliary to a shape and dimensions as hat my invention preferably comprises a" Patented Aug. 13, 1918.

able plate, the two elements being provided with apertures through which the exposure is made when the aperture in the movable plate passes the aperture in the holder.

1 T e holder preferably consists of a back or base 10, having a central aperture 11 formed therein and secured upon the rear surface of the base about this aperture, is a tubular member 12, of a shape and size correspondingto the lens tube or front opening of the camera. This tubular member may be conveniently formedby stamping out and bending back the metal in forming the aperture 11, or may consist of a separate plate attached to the back and the tubular portion thereof slitted longitudinally, as shown.

he device is readily attached to the camera by inserting this tubular member into the camera lens opening where it is frictionally held and can be easily removed therefrom The base 10 is Without the use of tools. preferablyvrectangular in shape and has its longitudinal edges 13 bent sharply inwardly and then upwardly and outwardly as illustrated in Fig. 3), whereby suitable parallel grooves 14, 14 are provided for the reception of the edges of a movable coacting diaphragm or plate 15. These edges 13 also provide suitable means whereby the device may be readily grasped between the fingers of the operator. Suitable inwardly extending stop lugs 16 and 17 are provided on one of the flanges 13, respectively at the upper end of the same and on the side thereof intermediate the ends, while an elongated finger 18 projects from the diaphragm or plate 15 above the adjacent flange 13, to cooperate with or engage said lugs at each end of its longitudinal movement. I

The diaphragm or plate 15 preferably comprises an elongated strip of metal approximately the same length as said holder, 1 that is provided intermediate its ends with an aperture 19 of substantially the same aperture 11 in the base, and one end edge, (preferably the upper edge) is bent laterally to provide a lip 20 or convenient means for the operator to grasp when setting the device.

Adjacent the upper end of the base, one of provided with a projection the 'flanges 13' is 21', that "registers withthe finger 18 when the diaphragm or plate 15 is in its set position, or, in other words, at the upper limit ofits movement. -'When the diaphragm or plate 15 has been -tion pass when the shutter is set,

lease the shutter.

set, a suitable destructible element 22 is placed over the finger 18 and projection 21 to temporarily secure these p'artstogether and prevent the gravitation or movement .0

the diaphragm or plate. This element 22 maybe of any convenient shape and material and is adapted to be ignited when the opera tor desires to make the exposure,- and as soon as the same has combusted or fused, it will release its'ihold upon the-parts 18 and 21 and permitthe diaphragm or plate 15 to move downwardly or gravitate in its guides whereby the aperture 19 passes. the aperture 11 andpermits light to enter. the lens. By inclining the device more to the horizontal, a slow movement ofthe diaphragm or plate 15 is obtained, orby moving it to a vertical position (Fig. 1), a rapid movement is thereby obtained. A convenient form of destructible element is illustrated in Fig. 5, which consists of an elongated strip of paper or other suitable material that has been treated with a solution of potassium nitrate (KNO orsaltpeter, to render the combustion' thereof more certain. Thestrip isprovicled with an, open slot 23 in one end portion, through ,whichthe finger and'projecand a slit 24 is out in the .opposite end-portion, Whereby several elements may in order tolengthenthe burning'of the element and increase the length of time to re Another manner of taining the siutter in set position consists in raising the diaphragm or plate 15 to its proper position and then inserting an inverted match 25 between the lug 17 and finger 18, as shown in Fig; 1 of thedrawings. Upon lgniting the head of-the match the same will burn and as soon as a' portion of the stem hasbecome destroyed and weakened, it will give way and permit the diaphragm or plate 15 to gravitate.

What I claim 1s 1. An auxiliary shutter for adapted to coact with the camera lens-opening and comprising a slidable plate having an opening therein adapted to be moved past the lens-opening, a guide therefor consisting of a movable plate of substantially U- shaped' cross-section and provided with longitudinal grooves in which said slidable plate isinounted, projections on said slide plate and said guide plate adapted to be brought into register with each other, and removable means coacting with said projections adapted to retain the latter in temporary registry.

fa An auxiliary shutter for cameras adaptedito coact withthe camera lens-openingandcomprising a slidableplate having an opening therein adapted to be moved Copies of this patent may be obtained iorfive cents each Thyafldressingfthe Washingtom-D. .G."

be linked together means adapted to retain said projections in temporary registry.

3. An auxiliary shutter for cameras adapted-to coact with a camera lens-opening and comprising a slidable plate'having an opening therein adapted to be moved past said lens-opening, a guide therefor having an opening adapted to register with the camera lens-openings, a tubular embossment surrounding said opening and coacting with the camera lens-opening. projections on said plate andg uide and means adapted to retain said projections in temporary registry.

4. An auxiliary shutter adapted to coact with a camera lens-opening comprising a base provided with an opening, means for securing same in front of the camera lensopen-i-ng,: a slide provided with an aperture coaetablewith the cameralens-opening and adapted to gravitate on saidbase, stops for said slide, members projecting from said base and slide, :and removable element co- .acting with said members whereby said slide is held against movement with the aperture thereiniout of register with the camera lens opening. V

.5. An auxiliary shutter for cameras adapted to coact with'the camera lens openingand comprising a slidable plate having an opening therein adapted to be moved past the lens-opening, means for preventing the operation of-said auxiliary shutter consisting ofa-strip. of combustible material, constructed 'to' temporarily retain relatively movable portions of said shutter in an adjusted position, said' strip of material being provided with means for receiving another like strip of combustiblematerial whereby theperiod of combustion before destruction is increased. i

6; An auxiliary shutter for cameras consistingof a base, a slide adapted to move upon said base-and provided with an. aperture adapted to coact with the cameralena opening, stops for limiting the movement of said slide, members projecting from said base and slide and a destructible element coacting with said membersand adapted to hold said slide against movement with the aperture therein out of register with the camera lens-opening. V

Signed at Chicago, county-of Cook and State of Illinois, this l lth'day of May, 1917.

j JESSE H. DOLBY. Witnesses:

.E. K. :LUNDY, Jr, H. SLACK. I

Commissioner of Yatents, 

